typedef.c

#include <stdio.h>
#include <stdlib.h>
 
typedef double number;
typedef number* numbers;
typedef size_t index;
typedef number (*function)(number);
 
numbers map(function f, numbers xs, size_t size) {
  numbers ys = malloc(size * sizeof(number));
  if(!ys) return 0;
  for(index i=0; i<size; ++i) ys[i] = f(xs[i]);
  return ys;
}
 
number sqr(number x) {
	return x*x;
}
 
int main(void) {
	number nats[] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0};
 
	numbers squares = map(sqr, nats, 10);
 
	if(squares) {
		printf("squares: ");
		for(int i=0; i<10; ++i)
			printf("%.0f ", squares[i]);
		free(squares);
	} else {
		printf("Sorry! No memory.");
	}
 
	return 0;
}

Вывод программы:

squares: 1 4 9 16 25 36 49 64 81 100